Amniocentesis provides a lot of valuable genetic information, but it is not without risk to mother and baby. Therefore, parents and practitioners must exercise a high level of responsibility in deciding whether or not to have this prenatal test.
This test tells a lot about the genetic makeup of your baby and reveals more common genetic defects. Amniocentesis is usually performed between the 12th and the 16th week, after the last menstrual period when there is enough fluid surrounding the baby that a sample is possible. Amniocentesis may also be performed in the last eight weeks of pregnancy. It takes a week or two to get the results on chromosomal abnormalities (and the baby’s sex). Results on conditions such as spinal defects, Hunter’s Syndrome, and Tay-sachs Disease are available the next day.
Using ultrasound to locate an area where baby and placenta are not in the way, the doctor inserts a long needle through the skin on the abdomen into the uterus and withdraws some amniotic fluid. These materials are then sent to genetic and biochemical laboratories for analysis. The whole procedure takes around thirty minutes.
The material obtained in amniocentesis reveals the gender of the baby, his or her chromosomal make-up, the maturity of the baby (especially the lungs) and whether or not he or she may have certain inherited diseases. There are various reasons your doctor may recommend amniocentesis such as if you already have a previous child with a genetic abnormality, inherited genetic disorder or other disease; if your AFP levels are high; or if you are over 35. While it is safe, it is not without a slight risk of damage to the organs of the baby, placenta, and umbilical cord, though ultrasound guidance reduces this risk considerably. There also is a 1 in 200 chance of inducing a miscarriage with amniocentesis.